Puberty in mammals is controlled by a complex interplay of endocrine and environmental variables. We propose a longitudinal series of studies to examine the hormonal parameters of sexual maturation in female rhesus monkeys, and to determine how social and physical characteristics of the environment regulate this process. Intact and ovariectomized females treated with estradiol (E2) will be studied from 12 months of age (prepuberty) through 48 months of age (young adult) with specific experiments demarcated at critical times during development. We will determine if maturation in this primate is characterized by a gradual decrease in the ability of E2 to inhibit the secretion of luteinizing hormone (LH) and follicle-stimulating hormone prior to first ovulation. Developmental changes inthe pulsatile secretion pattern of LH will be assessed to determine their precise temporal relationship to (1) the predicted decrease in E2 negative feedback on gonadotropin secretion, (2) menarche, and (3) the capacity to ovulate. As rhesus monkeys are seasonal breeders, attempts to induce on ovulatory surge of LH by E2 treatment at specific times during development will determine how age and annual photoperiodic changes control the occurrence of first ovulation. Furthermore, an examination of changes in serum patterns of adrenal androgens and growth hormone will determine how these hormones synergistically influence the decrease in E2 negative feedback on gonadotropin secretion and pubertal growth rates. Demographic variables also will be assessed to determine their influence on the hormonal progression of puberty and the outcome of pregnancy associated with first ovulation. The proposed experiments will elucidate the hormonal sequence of puberty in a primate species, and will thus provide a better understanding of how the brain and ovary interact to produce a reproductively viable adult. The examination will further clarify normal and abnormal pubertal development in humans.